Reversing valve-gear.



""- Patented May I4, 1901. H. c. CLAY.

REVERSING VALVE GEAR.

(Application filed July 21, 1000.)

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No. 673,859. Patented May l4, i90l. H. C. CLAY. REVERSING VALVE GEAR.

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HARRY C. CLAY, OF COLUMBUS, INDIANA, ASSIGNOR TO REEVES &

COMPANY, OF SAME PLACE.

REVERSING VALVE-GEAR.

SPECIFICATION forming part of Letters Patent No. 673,859, dated. May 14, 1901.

Application filed July 21, 1900.

To all whom it may concern:

Be it known that I, HARRY C. CLAY, a citizen of the United States, residing at Columbus, in the county of Bartholomew and State of Indiana, have invented a new and useful Reversing Valve-Gear, of which the following is a specification.

My invention relates to an improvement in valve-gears for steam-engines, especially of that type known as reversing-gears.

The economical working of a steam-engine requires that the point of cut-oi? be the same at both ends of the cylinder and that the portopening also be the same atboth ends. In a reversing-engine it is further desirable that this uniformity extend to both the over and under motions.

The obj eot of my present invention is therefore to produce a simple and efficient gear by means of which the engine may be easily reversed and by means of which the points of cut-ofi within a large range will bear the same relation to the stroke of the piston at both ends whether said piston be driving the crankshaft over or under.

A further object is to arrange the various elements so that the amount of lead shall be uniform for all points of cut-off and for either direction of motion.

The accompanying drawings illustrate my invention.

Figure 1 is a side elevation of an engine provided with my gear, the parts being in position to allow the engine to run over with a cut-off at five-eighths. Fig. 2 is a diagrammatic view showing the position of the parts to run under with cut-0E at five-eighths. Fig. 3 is a similar View showing the parts in position to run under with cut-oft at one-quarter. Fig. 4 is a similar view showing the parts in position to run over with cut-ofi at threeeighths.

In the diagrammatic views in order to show the essential parts on a larger scale the valve has been crowded toward the crank-shaft, thus bringing it beneath the valve-link. It will be readily understood that the point of attachment of the valve-link, so far as distance from the valve is concerned, is immaterial.

In the drawings,5 indicates the crank-shaft;

Serial No. 24,372. (No model.)

6, the crank-pin; 7, the connecting-rod, and 8 the cross-head pin, the said pin of course having the same movement as the piston. (Not shown.)

Mounted on the crank-shaft 5 is the usual eccentric 9, upon which is mounted an eccentric-strap 10, having a radial arm 11. Pivoted to the outer end of the arm 11 at the point 12 is a controlling-link 13, the opposite end of which is pivoted at 14 to the outer end of a reversing-lever 15, which lever is pivoted upon the frame at 16. trio-arm 11 at 17 (a point between and in line with the point 12 and the center of the eccentric) is a link 18, the opposite end of which is pivoted at 19 to the end of one arm of a bell-crank lever or rocker 20, pivoted at 21 upon the same side of the axis of the engine as the reversing-lever. Pivoted at 22 to the other arm of rocker-arm 20 is a valve-link 23, the opposite end of which is pivoted at 24 to the valve 25.

The controlling-link 13 and the reversingarm 15 are of exactly the same length, and the center 16 of the reversing-arm is so placed that when the piston is at either end of its stroke the point 12 of the eccentric-arm 11 will coincide with said center. The point 16 also lies within the quadrant formed by the axis of the engine and a line a, drawn from the center of the crank-shaft at right angles to said axis. The center of the eccentric 9 is not exactly opposite the center ofcrank, but is placed in advance of the opposite point at an angle substantially equal to the angle be tween the vertical or and the center 16. The position of the point 16 is also such that when the reversing-lever is in its medial position the resultant movement of the valve will be merely equal to the lap plus the lead.

That arm of the bell-crank lever 20 to which link 23 is attached is preferably arranged so as to have about the same movement upon each side of a line drawn at right angles to of a link 27. The opposite end of link 27 is Pivoted to the eccenthe engine-axis and through the pivotal point secured to an operating-lever 28, carrying the usual detent 29, arranged to engage the teeth of a segment 30.

In the diagrammatic views one position of the parts is indicated by the numerals given above, while the other position of the same parts for the corresponding and opposite point of cut-off is indicated by giving each numeral an exponent, as 6 6", &c.

In operation the action of the eccentric through the valve-link upon the valve is modified by the action of the controlling-link 13 upon the end of the eccentric-arm 11 and the action of the rocker or bellcrank lever,and these modifying influences are so arranged as to time and amount that the points of cutoff at both ends of the cylinder, whether the engine be running over or under, will at all times bear the same relation to the pistonstroke. The port-opening at both ends will also be substantially identical, as shown in Fig. 2.

Considerable care should be used in constructiug this device by properly proportioning the several parts, and for this reason I have prepared the drawings, especially the I diagrammatic views, accurately to scale.

I claim as my invention 1. In a reversing valve-gear, the combination with the crank-shaft, of an eccentric, an eccentric-arm mounted thereon, a reversinglever pivoted at a point between the axis of the engine and a line normal thereto through the shaft, a controllinglink, of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever and at the other end to the eccentric-arm, a link pivoted at one end to the eccentric-arm at a point between and in line with the eccentric center and the pivot of the controlling-link, intermediate connections between the link and the valve, and means for holding the reversing-lever in any desired posit-ion.

t gine and line normal thereto through'the shaft,

an eccentric secured to the shaft and offset from the crank substantially one hundred and eighty degrees less the angle between the reversing-lever center and the normal to the engine-axis through the shaft, an eccentricarm mounted thereon, a controlling-link, of

thelsame length as the reversing-lever, piv- .oted atone end to the end of the reversinglever, and at the other end to the eccentricarm," a, link, pivoted at one end to the eccentrio-arm at a point between and in line with the eccentric center and the pivot of the controlling-link, intermediate connections between the link and the valve, and means for holding the reversing-lever in any desired polever pivoted at a point between the axis of the engine and a line normal thereto through the shaft, a controlling-link of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever and at the other end to the eccentric-arm, a link pivoted at one end to the eccentric-arm at a point between and in line with the eccentric center and the pivot of the controlling-link, a bellcrank lever mounted on the same side of the engine-axis as the reversing-lever, and hav ing one ofits arms pivoted to said link, a valvelink connected at one end to the other arm of the bell-crank lever and at the other end to the valve, and means for holding the reversing-lever in any desired position, whereby a uniform cut-off and uniform port-opening may be had for either direction of motion of the engine.

4. In a reversing valve-gear, the combination with the crank-shaft, of a reversing-lever pivoted at a point between the axis of the en gine and a line normal thereto through the shaft, an eccentric secured to the shaft and offset from the crank substantially one hundred and eighty degrees less the angle between the reversing-lever center and the normal to the engine-axis through the shaft, an eccentric-arm mounted thereon,a controllinglink of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever and at the other end to the eccentric-arm, a link, pivoted at one end to theec centric-arm at a point between and in line with the eccentric center and the pivot-of'the controlling-link, a bell-crank lever mounted on the same side of the engine-axis as the reversing-lever, and having one of its arms pivoted to said link, a valve-link connected at one end to the other arm of the bell-crank lever and at the other end to the valve, and means for holding the reversing-lever in any desired position, whereby a uniform cut-off and uniform port-opening may be had for either direction of motion of the engine.

5. In a reversing valve-gear, the combination with the crank-shaft, of an eccentric, an eccentric-arm mounted thereon, a reversinglever pivoted at a point between the axis of the engine and a line normal thereto through the shaft, a controlling-link, of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever and at the other end to the eccentric-arm, a link pivoted at one end to the eccentric-arm at a point between the eccentric center and the pivot of the controlling-link, intermediate connections between the link and the valve, and means for holding the reversing-lever in any desired position.

6. In a reversing valve-gear, the combination with the crank-shaft, of a reversing-lever pivot-ed at a point between the axis of the en'- gine and line normal thereto through the shaft, an eccentric secured to the shaft and offset from the crank substantially one hundred and eighty degrees less the angle between the reversing lever center and the normal to the en gine-axis through the shaft, an eccentric-arm mounted thereon, a controlling-link, of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever, and at the other end to the eccentric-arm, a link, pivoted at one end to the eccentric-arm at a point between the eccentric center and the pivot of the controlling-link, intermediate connections between the link and the valve, and means for holding the reversing-lever in any desired position.

7. In a reversing valve-gear, the combination with the crank-shaft, of an eccentric, an eccentric-arm mounted thereon, a reversinglever pivoted at a point between the axis of the engine and a line normal thereto through the shaft, a controlling-link of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever and at the other end to the eccentric-arm, a link pivoted at one end to the eccentric-arm at a point between the eccentric center and the pivot of the controlling-link, a bell-crank lever mounted on the same side of the engineaxis as the reversing-lever, and having one of its arms pivoted to said link, a valve-link connected at one end to the other arm of the bell-crank lever and at the other end to the valve, and means for holding the reversinglever in any desired position, whereby a uniform cut-off and uniform port-opening may be had for either direction of motion of the engine.

8. In a reversing valve-gear, the combination with the crank-shaft, of areversing-lever pivoted at a point between the axis of the engine and a line normal thereto through the shaft, an eccentric secured to the shaft and offset from the crank substantially one hundred and eighty degrees less the angle be- .tween the reversing-lever center and the normal to the engine-axis through the shaft, an eccentric-arm mounted thereon, a controlling-link of the same length as the reversing-lever, pivoted at one end to the end of the reversing-lever and at the other end to the eccentric-arm, a link, pivoted at one end to the eccentric-arm at a point between the eccentric center and the pivot of the controlling-link, a bell-crank lever mounted on the same side of the engine-axis as the reversing-lever, and having one of its arms pivoted to said link, a valve-link connected at one end to the other arm of the bell-crank lever, and at the other end to the valve, and means for holding the reversing-lever in any desired position, whereby a uniform cut-off and uniform port-opening may be had for either direction of motion of the engine.

HARRY O. CLAY. Witnesses:

A. (J. DENISON, HARRY G. SCHOWE. 

